Comparisons among those with reported allergy, according to penicillin allergy testing result
| Characteristic | Tested negative (n=94) | Valid allergy or tested positive (n=31) | P value* |
| Gravidity during pregnancy, median (IQR) | 2 (1, 3) | 3 (1, 5) | 0.01 |
| Parity during pregnancy, median (IQR) | 1 (0, 1) | 1 (0, 2) | 0.11 |
| Age (years), mean (SD) | 30.2 (4.0) | 30.9 (4.7) | 0.40 |
| Prepregnancy BMI (kg/m2), median (IQR) | 24.6 (22.2, 29.4) | 24.2 (22.2, 27.2) | 0.39 |
| Alcohol use | 0.53 | ||
| Yes | 43 (45.7%) | 13 (41.9%) | |
| No | 48 (51.1%) | 18 (58.1%) | |
| Not documented | 3 (3.2%) | 0 (0.0%) | |
| Tobacco use | 0.16 | ||
| Yes | 5 (5.3%) | 4 (12.9%) | |
| No | 89 (94.7%) | 27 (87.1%) | |
| Illicit drug use | 0.009 | ||
| Yes | 1 (1.1%) | 4 (12.9%) | |
| No | 90 (95.7%) | 27 (87.1%) | |
| Not documented | 3 (3.2%) | 0 (0.0%) | |
| Marital status | 0.46 | ||
| Married or life partnership | 81 (86.2%) | 25 (80.6%) | |
| Single, divorced, separated or widowed | 13 (13.8%) | 6 (19.4%) | |
| Education level | 0.02† | ||
| High school degree or less education | 4 (4.3%) | 2 (6.5%) | |
| Associate degree or some college | 20 (21.3%) | 8 (25.8%) | |
| Bachelor’s degree or more | 70 (74.5%) | 18 (58.1%) | |
| Not documented | 0 (0.0%) | 3 (9.7%) | |
| Reported allergy | |||
| Penicillin and/or amoxicillin/ampicillin allergy | 0.001 | ||
| Penicillin only | 18 (19.1%) | 14 (45.2%) | |
| Amoxicillin/Ampicillin only | 70 (74.5%) | 12 (38.7%) | |
| Both penicillin and amoxicillin/ampicillin | 6 (6.4%) | 5 (16.1%) | |
| Multiple beta-lactam allergies | 0.06 | ||
| Yes (at least two of penicillin, amoxicillin/ampicillin, or cephalosporin) | 11 (11.7%) | 8 (25.8%) | |
| No | 83 (88.3%) | 23 (74.2%) | |
| Group B Streptococcus testing | 0.69 | ||
| Positive | 17 (18.1%) | 4 (12.9%) | |
| Negative | 71 (75.5%) | 24 (77.4%) | |
| Not documented or not done | 6 (6.4%) | 3 (9.7%) | |
| Pregnancy outcome | -- | ||
| Delivered at affiliated institution | 90 (95.7%) | 29 (93.5%) | |
| Delivered elsewhere | 2 (2.2%) | 0 (0.0%) | |
| Early pregnancy loss | 1 (1.1%) | 1 (3.2%) | |
| Lost to follow-up | 1 (1.1%) | 1 (3.2%) | |
| Delivery route‡ | 0.36 | ||
| Caesarean section | 26 (28.9%) | 11 (37.9%) | |
| Vaginal | 64 (71.1%) | 18 (62.1%) | |
| Gestational age (weeks), median (IQR)‡ | 39.3 (38.4, 40.1) | 39.3 (38.4, 39.7) | 0.49 |
| Birth weight (g), median (IQR)‡ | 3500 (3200, 3720) | 3410 (3170, 3680) | 0.57 |
IQR=25th and 75th percentiles.
*Comparisons between the groups were evaluated using the two-sample t-test for age, the Wilcoxon rank sum test for all other continuous or count variables and the χ2 test for all other variables.
†When the categories were further collapsed to compare those with versus without a bachelor’s degree or more (74.5% (70/94) vs 64.3% (18/28)), the difference did not attain statistical significance (p=0.29).
‡Restricted to those who delivered at the affiliated institution.
BMI, body mass index.